Platform Supports the Shortest Direct Electrical Connections between Two OSFP Transceivers

ABSTRACT

Two OSFP transceivers&#39; connectors&#39; footprints are placed on the opposite sides of a PCB board. The two footprints are aligned in a special way and the connections among the high speed signals&#39; pads of the two footprints are specially defined. Based on that, the high speed signals&#39; pads of the two footprints are connected through PCB traces and vias. Two OSFP electrical connectors are soldered onto the two footprints. So the electrical high-speed signals coming from two OSFP transceivers are directly connected in the shortest way when the two transceivers are respectively plugged into the two OSFP connectors.

FIELD OF APPLICATION OF THIS INVENTION

Telecommunication and Data communication industries' R&D, Testing andProduction.

BACKGROUND

OSFP transceivers are broadly applied in the Telecommunication and Datacommunication industry for exchange of information over distances. Theinterconnections in those applications are all about transceivers tohost system and host system to transceivers. However, the connectionsdirectly between OSFP transceivers had been not discussed and evenignored. Nevertheless, an interposer board supporting direct electricalconnections between two transceivers is very potential to establish afundamental platform, on which new applications will be developed andexisting design may be leveraged by using it. This invention willpresent what the fundamental interposer platform looks like and how itcan implements the adjustable length to the shortest and all uniformlength electrical connections for all the electrical high-speed signalscoming from two OSFP transceivers.

SUMMARY OF THE INVENTION

In order to achieve the best performance of electrical connectionsbetween high-speed signals coming from two OSFP transceivers, the twotransceivers need to be plugged into two OSFP electrical connectorsmounted on the opposite sides of a PCB interposer board. The two OSFPelectrical connectors are soldered or epoxied onto their footprints.Each footprint of the two electrical connectors consists of 60 pads and32 of them are defined as high-speed signals. The two footprints areindividually placed on different sides of the PCB interposer board andaligned as the way that all adjacent pads are lined up and spaced evenlyby looking through transparent view from either side of the PCBinterposer. Length adjustable PCB traces and vias are used to implementthe connection of each pair of specially mated pads, which areindividually located on the opposites of the PCB interposer board.Therefore, the electrical high-speed signals coming from the twotransceivers are connected through the electrical connectors,footprints' pads, length adjustable PCB traces and vias.

Overall, this invention is about a PCB interposer platform, whichenables the accomplishment of direct, uniform and shortest electricalconnections for all the high-speed signals coming from two OSFPtransceivers. This utility of the special way of making the connectionsbetween two OSFP electrical connectors distinguishes this solutionhaving adjustable length to the shortest capability, being capable tomake all connections uniform, taking minimum space and importantlyavoiding to use any RF cables.

BRIEF DESCRIPTION OF THE DRAWINGS

1. FIG. 1 is a drawing of an OSFP electrical connector's footprintFootprint A on the top side of a PCB (Top view).

2. FIG. 2 is a drawing of an OSFP electrical connector's footprintFootprint B on the bottom side of a PCB (Top transparent view).

3. FIG. 3 is a drawing of two OSFP electrical connectors' footprintsFootprint A and Footprint B disposed on the different sides of a PCB andaligned in a special way as shown (Top transparent view).

4. FIG. 4 is a drawing of how the high speed signals' pads of the twoOSFP electrical connectors' footprints Footprint A and Footprint B areconnected through PCB traces and vias on a PCB board when theconnections of the pads are defined in Type I (Top transparent view).

5. FIG. 5 is a drawing of how the high speed signals' pads of the twoOSFP electrical connectors' footprints Footprint A and Footprint B areconnected through PCB traces and vias on a PCB board when theconnections of the pads are defined in Type II (Top transparent view).

6. FIG. 6 is a 3D drawing of an OSFP electrical connector's footprintFootprint A disposed on the top side of a PCB board.

7. FIG. 7 is a 3D drawing of two OSFP electrical connectors' footprintsFootprint A and Footprint B respectively disposed and aligned in aspecial way on the top side and on the bottom side of a PCB board.

8. FIG. 8 is a 3D drawing of two OSFP electrical connectors Connector Aand Connector B respectively soldered onto their footprints Footprint Aand Footprint B, which are located on the top side and the bottom sideof a PCB board.

9. FIG. 9 is a 3D drawing of two OSFP transceivers Transceiver I andTransceiver II respectively plugged into their electrical connectorsConnector A and Connector B, which are mounted on the opposite sides ofa PCB board.

10. FIG. 10 is a 3D drawing of how high-speed electrical signals comingfrom two OSFP transceivers Transceiver I and Transceiver II areconnected through module edge card connectors, module electricalconnectors Connector A and Connector B, connectors' footprints FootprintA and Footprint B, PCB traces and vias.

11. Table 1 is a table showing the pin assignments of high-speed signalsand GND signals of the OSFP electrical connector's footprint Footprint Adisposed on the top side of a PCB board.

12. Table 2 is a table showing the pin assignments of high-speed signalsand GND signals of the OSFP electrical connector's footprint Footprint Bdisposed on the bottom side of a PCB board.

13. Table 3 is a table showing the Type I connections of the pads comingfrom the two OSFP electrical connectors' footprints Footprint A andFootprint B respectively disposed on the top side and the bottom side ofa PCB board.

14. Table 4 is a table showing the Type II connections of the padscoming from the two OSFP electrical connectors' footprints Footprint Aand Footprint B respectively disposed on the top side and the bottomside of a PCB board.

DESCRIPTION OF THE EMBODIMENT

1. An OSFP electrical connector's PCB footprint Footprint A on the topside of a PCB board is shown in FIG. 1 (Top View). There are 60soldering pads in the footprint. Each pad is assigned a unique number tostand for the physical location of the pad in the footprint.

2. The OSFP electrical connector's PCB footprint Footprint A's somesoldering pads are defined as high-speed signals and GND signals, andthe pads' pin assignments are shown in Table 1. The numbers in the Table1 are corresponding to Footprint A's pads' numbers and stand for thephysical locations of the soldering pads in Footprint A shown in FIG. 1.

3. An OSFP electrical connector's PCB footprint Footprint B on thebottom side of a PCB board is shown in FIG. 2 (Top Transparent View).There are 60 soldering pads in the footprint. Each pad is assigned aunique number to stand for the physical location of the pad in thefootprint.

4. The OSFP electrical connector's PCB footprint Footprint B's somesoldering pads are defined as high-speed signals and GND signals, andthe pads' pin assignments are shown in Table 2. The numbers in the Table2 are corresponding to the Footprint B's pads' numbers and stand for thephysical locations of the soldering pads in Footprint B shown in FIG. 2.

5. As shown in FIG. 3 , OSFP electrical connector Connector A'sfootprint Footprint A is placed on the top side of a PCB board, and OSFPelectrical connector Connector B's footprint Footprint B is placed onthe bottom side of the same PCB board. Perpendicularly looking throughtransparent view from top side of the PCB board, the two footprints arealigned as the way that all adjacent pads are lined up and spacedevenly. The pads above the original numbers are from Footprint A on thetop side of the PCB board, and the pads below the mirrored numbers arefrom Footprint B on the bottom side of the PCB board. The numbers belowthe pads are the corresponding pad-numbers shown in FIG. 1 and Table 1;and the numbers above the pads are the corresponding pad-numbers shownin FIG. 2 and Table 2.

6. As shown in FIG. 1 and Table 1, Footprint A has high-speed signalsand GND signals, and as shown in FIG. 2 and Table 2, Footprint B alsohas high-speed signals and GND signals; and the connections between thehigh-speed signals from Footprint A and Footprint B are defined as theType I shown in Table 3. In Table 3, the numbers in the shades ofbackslash lines are from Footprint A and the numbers in the shades offorward slash lines are from the Footprint B, and the numbers in theshades of horizontal lines are from Footprint A and the numbers in theshades of vertical lines are from Footprint B.

The connection mappings are as the followings:

-   -   Footprint A's pad 2 is connected to Footprint B's pad 29,    -   Footprint A's pad 3 is connected to Footprint B's pad 28,    -   Footprint A's pad 5 is connected to Footprint B's pad 26,    -   Footprint A's pad 6 is connected to Footprint B's pad 25,    -   Footprint A's pad 8 is connected to Footprint B's pad 23,    -   Footprint A's pad 9 is connected to Footprint B's pad 22,    -   Footprint A's pad 11 is connected to Footprint B's pad 20,    -   Footprint A's pad 12 is connected to Footprint B's pad 19;    -   Footprint A's pad 19 is connected to Footprint B's pad 12,    -   Footprint A's pad 20 is connected to Footprint B's pad 11,    -   Footprint A's pad 22 is connected to Footprint B's pad 9,    -   Footprint A's pad 23 is connected to Footprint B's pad 8,    -   Footprint A's pad 25 is connected to Footprint B's pad 6,    -   Footprint A's pad 26 is connected to Footprint B's pad 5,    -   Footprint A's pad 28 is connected to Footprint B's pad 3,    -   Footprint A's pad 29 is connected to Footprint B's pad 2;    -   Footprint A's pad 32 is connected to Footprint B's pad 59,    -   Footprint A's pad 33 is connected to Footprint B's pad 58,    -   Footprint A's pad 35 is connected to Footprint B's pad 56,    -   Footprint A's pad 36 is connected to Footprint B's pad 55,    -   Footprint A's pad 38 is connected to Footprint B's pad 53,    -   Footprint A's pad 39 is connected to Footprint B's pad 52,    -   Footprint A's pad 41 is connected to Footprint B's pad 50,    -   Footprint A's pad 42 is connected to Footprint B's pad 49;    -   Footprint A's pad 49 is connected to Footprint B's pad 42,    -   Footprint A's pad 50 is connected to Footprint B's pad 41,    -   Footprint A's pad 52 is connected to Footprint B's pad 39,    -   Footprint A's pad 53 is connected to Footprint B's pad 38,    -   Footprint A's pad 55 is connected to Footprint B's pad 36,    -   Footprint A's pad 56 is connected to Footprint B's pad 35,    -   Footprint A's pad 58 is connected to Footprint B's pad 33,    -   Footprint A's pad 59 is connected to Footprint B's pad 32.

7. As shown in FIG. 1 and Table 1, Footprint A has high-speed signalsand GND signals, and as shown in FIG. 2 and Table 2, Footprint B alsohas high-speed signals and GND signals; and the connections between thehigh-speed signals from Footprint A and Footprint B are defined as theType II shown in Table 4. In Table 4, the numbers in the shades ofbackslash lines are from Footprint A and the numbers in the shades offorward slash lines are from the Footprint B, and the numbers in theshades of horizontal lines are from Footprint A and the numbers in theshades of vertical lines are from Footprint B.

The connection mappings are as the followings:

-   -   Footprint A's pad 2 is connected to Footprint B's pad 28,    -   Footprint A's pad 3 is connected to Footprint B's pad 29,    -   Footprint A's pad 5 is connected to Footprint B's pad 25,    -   Footprint A's pad 6 is connected to Footprint B's pad 26,    -   Footprint A's pad 8 is connected to Footprint B's pad 22,    -   Footprint A's pad 9 is connected to Footprint B's pad 23,    -   Footprint A's pad 11 is connected to Footprint B's pad 19,    -   Footprint A's pad 12 is connected to Footprint B's pad 20;    -   Footprint A's pad 19 is connected to Footprint B's pad 11,    -   Footprint A's pad 20 is connected to Footprint B's pad 12,    -   Footprint A's pad 22 is connected to Footprint B's pad 8,    -   Footprint A's pad 23 is connected to Footprint B's pad 9,    -   Footprint A's pad 25 is connected to Footprint B's pad 5,    -   Footprint A's pad 26 is connected to Footprint B's pad 6,    -   Footprint A's pad 28 is connected to Footprint B's pad 2,    -   Footprint A's pad 29 is connected to Footprint B's pad 3;    -   Footprint A's pad 32 is connected to Footprint B's pad 58,    -   Footprint A's pad 33 is connected to Footprint B's pad 59,    -   Footprint A's pad 35 is connected to Footprint B's pad 55,    -   Footprint A's pad 36 is connected to Footprint B's pad 56,    -   Footprint A's pad 38 is connected to Footprint B's pad 52,    -   Footprint A's pad 39 is connected to Footprint B's pad 53,    -   Footprint A's pad 41 is connected to Footprint B's pad 49,    -   Footprint A's pad 42 is connected to Footprint B's pad 50;    -   Footprint A's pad 49 is connected to Footprint B's pad 41,    -   Footprint A's pad 50 is connected to Footprint B's pad 42,    -   Footprint A's pad 52 is connected to Footprint B's pad 38,    -   Footprint A's pad 53 is connected to Footprint B's pad 39,    -   Footprint A's pad 55 is connected to Footprint B's pad 35,    -   Footprint A's pad 56 is connected to Footprint B's pad 36,    -   Footprint A's pad 58 is connected to Footprint B's pad 32,    -   Footprint A's pad 59 is connected to Footprint B's pad 33.

8. As shown in FIG. 4 , for Type I connections, each pair of mated padsdefined in Table 3 are connected through length adjustable PCB tracesand at least one through hole via. The pads on the top side of a PCBboard and the pads on the bottom side of the PCB board are 100%overlapped in terms of top transparent view. The length adjustable PCBtraces on the top side and the length adjustable PCB traces on thebottom side are uniformly symmetrical and also 100% overlapped in termsof top transparent view. Each through hole via is connected to the PCBtraces on the top of the PCB and the PCB traces on the bottom of thePCB.

9. As shown in FIG. 5 , for Type II connections, each pair of mated padsdefined in Table 4 are connected through length adjustable PCB tracesand at least one through hole via. The pads on the top side of a PCBboard and the pads on the bottom side of the PCB board are 100%overlapped in terms of top transparent view. The length adjustable PCBtraces on the top side and the length adjustable PCB traces on thebottom side are uniformly symmetrical in terms of top transparent view.Each through hole via is connected to the PCB traces on the top of thePCB and the PCB traces on the bottom of the PCB.

10. OSFP electrical connector Connector A's footprint Footprint A isplaced on the top of a PCB board as shown in FIG. 6 .

11. As shown in FIG. 7 , OSFP electrical connector Connector B'sfootprint Footprint B is placed on the bottom side of the same PCB boardshown in FIG. 6 . And the two footprints Footprint A and Footprint B arealigned the way as shown in FIG. 3 .

12. As shown in FIG. 8 , OSFP electrical connectors Connector A andConnector B are individually soldered onto their footprints Footprint Aand Footprint B, which are placed on the opposite sides of a PCB boardand specially aligned as the way shown in FIG. 3 .

13. As shown in FIG. 9 , OSFP transceivers Transceiver I and TransceiverII are respectively plugged into their electrical connectors Connector Aand Connector B, which are individually mounted on Footprint A on thetop side of a PCB and Footprint B on the bottom side of the PCB board.

14. As shown in FIG. 10 , the high-speed signals (shown in Table 1) fromOSFP transceiver Transceiver I and the high-speed signals (shown inTable 2) from OSFP transceiver Transceiver II are directly connectedelectrically through Transceiver l's edge card connector, Connector A,Footprint A, PCB traces, vias, Footprint B, Connector B and TransceiverII's edge card connector in the shortest way.

1: An interposer comprising: The first OSFP electrical connectorConnector A and its footprint Footprint A disposed on the top surface ofa substrate, and the second OSFP electrical connector Connector B andits footprint Footprint B disposed on the bottom surface of thesubstrate, wherein Footprint A has 8 pairs of differential transmittingsignal pads and 8 pairs of differential receiving signal pads; FootprintB also has 8 pairs of differential transmitting signal pads and 8 pairsof differential receiving signal pads. The 8 pairs of differentialtransmitting signal pads of Footprint A are connected to thecorresponding 8 pairs of differential receiving signal pads of FootprintB; The 8 pairs of differential transmitting signal pads of Footprint Bare connected to the corresponding 8 pairs of differential receivingsignal pads of Footprint A. Each of the 32 pad to pad connections isimplemented through length adjustable metal traces plus at least onemetal plated through hole via, or through length adjustable metal tracesplus at least two metal plated stacked vias or staggered vias. Thelength adjustable metal traces for each of the 32 pad to pad connectionsare further specified that the total length of all segments is in rangeof 0 mm to 200 mm, including 0 mm; and additionally the lengthadjustable metal traces among the 16 pairs (32 pad to pad) of theconnections from transmitting pads to receiving pads could be uniformlysymmetrical or in different forms. 2: The OSFP electrical connectorConnector A in claim 1 is compliance with OSFP electrical connector“Single Row SMT Connector” in “OSFP Module Specification Rev 4.1”. 3:The OSFP electrical connector Connector B in claim 1 is compliance withOSFP electrical connector “Single Row SMT Connector” in “OSFP ModuleSpecification Rev 4.1”. 4: The OSFP electrical connector Connector A'sfootprint in claim 1 is the synonym of Host PCB layout pattern in “OSFPModule Specification Rev 4.1” and compliance with the Host PCB layoutpattern in “OSFP Module Specification Rev 4.1”. 5: The OSFP electricalconnector Connector B's footprint in claim 1 is the synonym of Host PCBlayout pattern in “OSFP Module Specification Rev 4.1” and compliancewith the Host PCB layout pattern in “OSFP Module Specification Rev 4.1”.6: The Footprint A's pads in claim 1 is the synonym of the Host PCBlayout pattern pads in “OSFP Module Specification Rev 4.1” and arecompliance with the Host PCB layout pattern pads in “OSFP ModuleSpecification Rev 4.1”. 7: The Footprint B's pads in claim 1 is thesynonym of the Host PCB layout pattern pads in “OSFP ModuleSpecification Rev 4.1” and are compliance with the Host PCB layoutpattern pads in “OSFP Module Specification Rev 4.1”. 8: The 32 pad topad connections in claim 1 are defined as Type I as the followings:Footprint A's pad 2 is connected to Footprint B's pad 29, Footprint A'spad 3 is connected to Footprint B's pad 28, Footprint A's pad 5 isconnected to Footprint B's pad 26, Footprint A's pad 6 is connected toFootprint B's pad 25, Footprint A's pad 8 is connected to Footprint B'spad 23, Footprint A's pad 9 is connected to Footprint B's pad 22,Footprint A's pad 11 is connected to Footprint B's pad 20, Footprint A'spad 12 is connected to Footprint B's pad 19, Footprint A's pad 19 isconnected to Footprint B's pad 12, Footprint A's pad 20 is connected toFootprint B's pad 11, Footprint A's pad 22 is connected to Footprint B'spad 9, Footprint A's pad 23 is connected to Footprint B's pad 8,Footprint A's pad 25 is connected to Footprint B's pad 6, Footprint A'spad 26 is connected to Footprint B's pad 5, Footprint A's pad 28 isconnected to Footprint B's pad 3, Footprint A's pad 29 is connected toFootprint B's pad 2, Footprint A's pad 32 is connected to Footprint B'spad 59, Footprint A's pad 33 is connected to Footprint B's pad 58,Footprint A's pad 35 is connected to Footprint B's pad 56, Footprint A'spad 36 is connected to Footprint B's pad 55, Footprint A's pad 38 isconnected to Footprint B's pad 53, Footprint A's pad 39 is connected toFootprint B's pad 52, Footprint A's pad 41 is connected to Footprint B'spad 50, Footprint A's pad 42 is connected to Footprint B's pad 49,Footprint A's pad 49 is connected to Footprint B's pad 42, Footprint A'spad 50 is connected to Footprint B's pad 41, Footprint A's pad 52 isconnected to Footprint B's pad 39, Footprint A's pad 53 is connected toFootprint B's pad 38, Footprint A's pad 55 is connected to Footprint B'spad 36, Footprint A's pad 56 is connected to Footprint B's pad 35,Footprint A's pad 58 is connected to Footprint B's pad 33, Footprint A'spad 59 is connected to Footprint B's pad
 32. 9: The 32 pad to padconnections in claim 1 also could be defined as Type II as thefollowings: Footprint A's pad 2 is connected to Footprint B's pad 28,Footprint A's pad 3 is connected to Footprint B's pad 29, Footprint A'spad 5 is connected to Footprint B's pad 25, Footprint A's pad 6 isconnected to Footprint B's pad 26, Footprint A's pad 8 is connected toFootprint B's pad 22, Footprint A's pad 9 is connected to Footprint B'spad 23, Footprint A's pad 11 is connected to Footprint B's pad 19,Footprint A's pad 12 is connected to Footprint B's pad 20, Footprint A'spad 19 is connected to Footprint B's pad 11, Footprint A's pad 20 isconnected to Footprint B's pad 12, Footprint A's pad 22 is connected toFootprint B's pad 8, Footprint A's pad 23 is connected to Footprint B'spad 9, Footprint A's pad 25 is connected to Footprint B's pad 5,Footprint A's pad 26 is connected to Footprint B's pad 6, Footprint A'spad 28 is connected to Footprint B's pad 2, Footprint A's pad 29 isconnected to Footprint B's pad 3, Footprint A's pad 32 is connected toFootprint B's pad 58, Footprint A's pad 33 is connected to Footprint B'spad 59, Footprint A's pad 35 is connected to Footprint B's pad 55,Footprint A's pad 36 is connected to Footprint B's pad 56, Footprint A'spad 38 is connected to Footprint B's pad 52, Footprint A's pad 39 isconnected to Footprint B's pad 53, Footprint A's pad 41 is connected toFootprint B's pad 49, Footprint A's pad 42 is connected to Footprint B'spad 50, Footprint A's pad 49 is connected to Footprint B's pad 41,Footprint A's pad 50 is connected to Footprint B's pad 42, Footprint A'spad 52 is connected to Footprint B's pad 38, Footprint A's pad 53 isconnected to Footprint B's pad 39, Footprint A's pad 55 is connected toFootprint B's pad 35, Footprint A's pad 56 is connected to Footprint B'spad 36, Footprint A's pad 58 is connected to Footprint B's pad 32,Footprint A's pad 59 is connected to Footprint B's pad
 33. 10: Theinterposer in claim 1, wherein variations or modifications withoutdeparting the spirit of the 32 pad to pad connections in claim 8 couldbe made to the Footprint A in claim 1 and the Footprint B in claim 1, oreither Footprint A in claim 1 or Footprint B in claim
 1. For example,adding extra pads, removing some pads, changing the pads' sizes ormaking the pads' locations offset. 11: The interposer in claim 1,wherein variations or modifications without departing the spirit of the32 pad to pad connections in claim 9 could be made to the Footprint A inclaim 1 and the Footprint B in claim 1, or either Footprint A in claim 1or Footprint B in claim
 1. For example, adding extra pads, removing somepads, changing the pads' sizes or making the pads' locations offset. 12:A platform comprising: The interposer in claim 1, wherein the OSFPelectrical connector Connector A in claim 1 is soldered (or epoxied)onto the Footprint A in claim 1 and the OSFP electrical connectorConnector B in claim 1 is soldered (or epoxied) onto the Footprint B inclaim 1; The first OSFP transceiver module Transceiver I is plugged inthe Connector A in claim 1 and the second OSFP transceiver moduleTransceiver II is plugged in the Connector B in claim
 1. 13: Theplatform in claim 12 provides the method of direct (not through anyICs), cableless (without using any RF-cables) and uniform capableelectrical high-speed connections for the electrical high-speed signalsbetween the first OSFP transceiver module Transceiver I in claim 12 andthe second OSFP transceiver module Transceiver II in claim
 12. 14:Either the first OSFP transceiver module Transceiver I in claim 12 orthe second OSFP transceiver module Transceiver II as in claim 12 doesnot have to be compliance with “OSFP Module Specification Rev 4.1”, andcan be a Form Factor Pluggable SQA (Signal Quality Analyzer), a FormFactor Pluggable DCA (Data Communication Analyzer) or Form FactorPluggable FEC (Forward Error Correction) Network Traffic Tester.